Volume 2 Issue 4, April 2010

In the sink-or-swim world of academia, Bruce C. Gibb considers what support structures should be put in place for those who have only just entered the water.

The interactions of electrons and water molecules are not just of great fundamental interest but are also studied to understand the role electrons have in damaging biomolecules. Now using ultrafast photoelectron spectroscopy, key details about the energy and lifetime of the hydrated electron in bulk and at an interface have been determined.

Macrocyclic compounds can serve as hosts for smaller organic molecules, but precise control over the uptake and release of the guests remains challenging. Now, a host–guest system has been built that responds to the addition of metal ions, showing promise for drug-delivery applications.

Electrochemistry has so far been mostly centred around measuring factors and coefficients. Through the reversible reduction and oxidation of an electrode coating formed from three-dimensional hybrid aniline–gold nanoparticles, it has now moved on to controlling the pH of a solution, thus triggering specific reactions.

The convergent total synthesis of the pore-forming polytheonamide B — a linear peptide natural product — pokes holes through perceived limitations in de novo peptide synthesis, and provides access to novel synthetic membrane channels.

A strong acid catalyst and a small change to one reactant have transformed a 37-year-old 'curiosity' into a useful chemical reaction that has great potential in organic synthesis.

Rare-earth metal dialkyl complexes can be readily transformed into the corresponding cationic monoalkyl species — which have been shown to catalyse a range of (co)polymerization processes — as well as into polyhydride complexes that have unique structures and a rich reaction chemistry.

Fullerene cages that break the isolated pentagon rule are rare and often unstable. Now a range of fullerenes that feature three sequentially fused pentagons of carbon have been stabilized by chlorination.

The existence of solvated electrons bound at the liquid/water surface has not, until now, been proved experimentally. Here, using ultrafast photoelectron spectroscopy, the existence, vertical binding energies and lifetimes of solvated electrons bound at the water-surface/vacuum interface, and in bulk solution, have been revealed.

Polytheonamide B is a large non-ribosomal peptide with very high bioactivity. The synthesis described here includes the first preparation of several non-proteinogenic amino acids and a general coupling strategy for large non-natural peptides. The synthesis is a key step necessary to understand and utilize the bioactivity of this and similar compounds.

Formic acid fuel cells require nanosized intermetallic nanoparticles as anode catalysts, but current techniques are poor at producing the small size required. Now, surface-modified ordered mesoporous carbons have been used to produce nanocrystallites as small as 1.5 nm that are extremely active catalysts.

A triflimide-catalysed rearrangement of N-allylhydrazones has been developed that allows for the generation of a sigma bond between two unfunctionalized sp³ carbons such that no clear marker remains for how the bond was formed. This traceless bond construction offers new avenues for convergent fragment coupling in synthetic strategies.

Stepwise deuteration of protonated methane CH₅⁺ — a fluxional structure that undergoes ‘hydrogen scrambling’ — leads to dramatic changes in the infrared spectra of the isotopologues. The spectra can be assigned using ab initio quantum simulations that account for the non-classical occupation — by H and D atoms — of topologically different sites within the molecule.

Steric, torsion, stereoelectronic and polar effects are widely used to explain and predict the stereochemical outcome of synthetic organic reactions. Here, the asymmetric distortion of the reactant is considered and used to explain the observed stereoselectivity where these accepted models are unable to provide a clear prediction.

A wide range of porous framework materials has been assembled with a modular approach that takes advantage of prefabricated structural building units (SBUs). Now, it has been shown that functional all-inorganic frameworks can be made from a macrocyclic polyoxometalate SBU — that has a built-in aperture approximately 1 nm in diameter — linked together with redox-switchable metal ions.

The reactivity of organoaluminium reagents makes them particularly attractive nucleophiles for a wide range of organic reactions. Here, the use of metal halide catalysts provides access to functionalized organoaluminium reagents directly from the metal. The utility of these organoaluminium reagents is then demonstrated by their reaction with a wide variety of electrophilic coupling partners.

Nanotubular structures made from different materials are being investigated for applications ranging from sensing to drug delivery, but controlling how they interact with ‘cargo’ molecules has proved challenging. Now, the selective uptake, precise positioning and triggered release of gold nanoparticles has been achieved with nanotubes assembled from triangular DNA building blocks.

Gold nanoparticles can catalyse oxidation reactions in remarkably mild conditions and have excited much interest in recent years. With experimental studies disagreeing over the size of the most active nanoparticles, density functional calculations have now shown that limiting the particle size to below two nanometres is crucial.

Ram Mohan looks at how bismuth — a remarkably harmless element among the toxic heavy metals in the periodic table — has sparked interest in areas varying from medicinal to industrial chemistry.

April 2010 marks the first anniversary of the launch of Nature Chemistry. To celebrate, we have put together a compilation of our favourite articles from the first 12 issues. The selection, which is free until the end of June 2010, reflects the breadth of topics covered byNature Chemistry. We hope you enjoy it.